Hand sanitizer and anti-bacterial soaps are fine to use and even better to keep handy when you're sick. But, using them too much early on in life can result in allergies.

Flickr User Valerie Everett
Flickr User Valerie Everett

That's according to a recent study which finds that the immune system needs to be exposed to irritants and bacteria so it can learn how to fight against them.

"Allergy is the immune response to one's environment. If the environment is sterile, meaning nothing stimulates it, it leads one to be open to other immune responses, like allergies," said said Dr. Leonard Bielory, Professor at Rutgers University and attending at Robert Wood Johnson University Hospital. "What has evolved from what has become known as the 'hygiene hypothesis,' is the cleaner the environment, the more allergies are likely. The dirtier, or the more exposed a child is early on in life, the less likely they will have severe allergies later on in life. So, a sterile environment, a clean environment or an ultra-clean environment may not be as healthy as people think."

Stimulating Your Immune System

"An ultra-clean environment is obviously important for a child with some type of immunodeficiency where they can't fight infection. But, children without such issues who are growing can fight infection and their immune systems have to be stimulated in order to do so. That's one of the reasons we give vaccinations. It seems that the more they are exposed, the less allergic they will be," said Bielory.

How important is it to carry hand sanitizer with you at all times?

"It's one thing if you're sick and you're going to shake someone's hand. When you have a cold or virus, it is important to use hand sanitizer and wash your hands because washing your hands is the number one way you can decrease transmission of infection," said Bielory. "But, when you are not sick, it is not critically necessary to use hand sanitizer. I've noticed that many commercial stores have hand sanitizers all over the place. Again, not critically necessary unless you're sick or unless you could potentially transfer infection through your hands. So, the rule of thumb is, if you're coughing, cover your mouth with your arm instead of your hand and if you're sick, wash your hands regularly."